VES-80清洁压裂液实验研究

清洁压裂液在交联、破胶机理上完全不同于常规压裂液,清洁压裂液采用特殊的低分子量表面活性剂为稠化剂,基本无水不溶物,对储层伤害很小.VES-80清洁压裂液是一种无聚合物的粘弹性液体,靠一种特殊合成的低分子量表面活性剂,在一定浓度的盐溶液介质条件下,形成蠕虫状胶束并缠结成网状结构而将水增稠,达到交联目的;当遇到有机物或其它亲油性物质时,蠕虫状胶束被分解成小球状胶束,网状结构也被破坏,溶液粘度降低,达到压裂液破胶目的.试验结果表明,VES-80清洁压裂液抗剪切、携砂、破胶性能良好,几乎无水不溶物,对储层无二次伤害;该压裂液组成简单,配制方便,现场施工便利,可满足现场施工要求.

Laboratory research on clean fracturing fluid VES-80

Clean fracturing fluid is totally different from those of the conventional ones in respects to mechanisms of cross linking and breaking. Taking a particular low molecule surfactantas the thicker, its liquid efficiency is heighten with little water insoluble, and causes little damage to productive formation. Clean fracturing fluid VES 80 is a visco elastic liquid containing no polymer. As a novel fluid system, the cross linking is established on a net structure formed by wormlike micelleswinding in the presence of a particular small molecule surfactant and some volume salt solution, and when the wormlike micellesencounter with an orgnic compound or others exhibiting oil wetting behavior, they will be decompositedinto smaller balls, resulting in viscosity decline of the fluid where the breaking occur. The primary composition of clean fracturing fluid VES 80 was introduced and its properties were tested in lab.. Experiment results show that fluid VES 80 exhibits excellent shearing resistance property, sand carrying capacity and breaking ability; with little water insoluble impurities, the fluid produce nearly no secondary damage to the productive formation. By using this product, the preparation was convenient and the operation was easy for its simple composition.